This imposition was by necessity. Before creation, Beings existed in isolation and without relationships - thus direction, purpose and meaning in a creation based-upon Love emerged only after primary creation.
In this sense, also, freedom and the capacity for an agency based on distinguishing the self from the not-self was only possible post-creation.
(i.e. We cannot know we are a self until after we know of other selves.)
Therefore it was impossible for any Being to opt-out of creation, until after creation, because there could be no consent to creation, nor of 'opting', until after creation had-happened -- hence the necessity for its imposition.
But Love is by mutual consent only; and this meant that Beings were 'incorporated' into primary creation without consent; and (it seems) some of them withdrew consent almost immediately.
To be clear: all the Beings of creation (even Satan, the first rebel against God) have been, even if briefly, subordinated to God's creation.
Probably some who withdrew consent - who rapidly opted-out of creation - were incapable of Love; probably others were capable of Love, but did Not wish to make Love the basis of 'organization'...
Those who opted-out include what we regard as Satan and the demons - in other words these were never-incarnated spirit Beings.
Because primary creation cannot be undone or reversed (because now Beings Know about each other) the 'rebels' ultimate or distal 'goal' (insofar as they are explicitly aware of it) is a power-based reality; in which Beings are in a situation of antagonism and attempted domination or exploitation - which themselves (and, maybe, some recruits?) as the dominant exploiters.
In a nutshell; the demons, and all others who have rejected Love/ God/ creation at some later point - aspire to a reality based-on relationships of power and selfishness.
Thus they have chosen to opt-out of primary creation.
In primary creation (which was all of creation before the advent of Jesus Christ) God operates as a power acting-upon us, i.e. upon Beings.
In a sense; God does creation to us.
Living in creation is therefore the default situation; from-which we would need to opt-out if we did not want it.
This imposed-creation situation was recognized by all the old religions, and still is recognized (at least implicitly) by those religions that have a supreme God but do not recognize the truth and desirability of Jesus Christ.
Therefore the Old Gods, and the understanding of the ancient monotheistic God of the Hebrews or the later God of Islam - regard God as primarily power.
And such a God of non-optional imposed-creation demands of us obedient service above all else - which goes-with a relationship as essentially one of awe, fear, submission, propitiation etc. That is; a relationship analogous to that of an ignorant peasant towards the absolute Emperor of vast domains.
As I said; this attitude is a natural consequence of the primary creation in which creation was done to us. Our understanding-of and relationship-to God is of one who is done-to - who is insignificant; not one who participates-in, or who himself contributes something of substantive value.
The secondary creation was made-to-happen by Jesus Christ; and this fundamentally changed our relation with God.
The second creation was (for the first time) an opt-in situation, and made God (potentially) the supreme beloved Father of a vast family -- rather than King of 'a people'.
Since the second creation; God no longer requires or desires us to regard him as primarily a power, but a loving parent; God no longer requires our obedient submission to His imposed authority, but invites our loving participation in his continuing work of creation.
The secondary creation involves Beings that are already free agents, and who know about other Beings; it involves making the choice of an eternal commitment to live harmoniously with other beings guided by, and in a condition of, mutual love.
This secondary creation mode-of-Being is achieved by the willing transformation that is resurrection - and the second creation is called Heaven, a situation where we go by our own active desire.
In the second creation; we are Not supposed-to regard God as remote, incomprehensible, as like a Monarch or a Judge before which we ought-to abase ourselves in submission and obedience...
And we are Not supposed to regard our-selves as insignificant, superfluous, functionless... but as irreplaceable and able to add some-thing worthwhile to what-is - across eternity.
We are instead supposed to have an attitude to God of love, gratitude, joy, positivity, energy, excitement; a desire to bring the best of ourselves to the work of God's divine family; to join-in with the plans of divine creating.
Because the second creation is opt-in; some who reject God include those who opted-out after becoming incarnated into this mortal life. They lived in primary creation as pre-mortal spirits without opting-out; but after they were born as Men, they made the decision (whether before or after death) "not to opt-into" the second creation.
To clarify: Because the second creation is opt-in; there are those who positively reject the second or the first creation (presumably Satan and the demons, but probably others too), but also those who negatively do not want the second creation. These may still be prepared not to opt-out from the first creation - these would include many religious but-not-Christian people, including some self-identified Christians who actually don't want what Jesus offers!.
The difference between dwelling in the first and second creation is therefore a vital difference for Christians to grasp; if they are not to fall-into an attitude to God that fits the opt-out primary, but not the opt-in secondary creation.
"Christians" who get their idea of God from the pre-Jesus era of the Jews of the Old Testament, tend to have the 'negative' attitudes of the first creation (e.g. the primacy of obedience to power), but fail to understand or embrace the essential qualitative difference that Jesus made.
Such people are sometimes therefore de facto non-Christians, in terms of their attitudes and expectations, and their desires.
But the reality is that Jesus Christ changed the fundamental possibilities of reality; things are possible since Jesus that were not possible before Jesus.
The Big Question is whether we personally want what Jesus made possible - or not?
If we want it, we each must choose it.
We must then opt-in...
H/T - Loic Simond for a comment that triggered the thinking that led to this post.